1. Field of the Invention
The present invention relates to an ink-jet recording device that comprises a recording head, for ejecting ink droplets through nozzle openings in response to print signals, and an ink cartridge for supplying ink to the recording head.
2. Related Art
For the process by which pressure is applied to ink in a pressure generation chamber using pressurization means, such as a piezoelectric vibrator, and is ejected as ink droplets through nozzle openings of several tens of xcexcm, a conventional ink-jet recording device has a filter that is inserted into a flow path connecting an ink cartridge to a recording head to prevent dust and large air bubbles from entering the pressure generation chamber, so that the clogging of the nozzle openings due to dust in the ink and the flow of air bubbles into the generation pressure chamber does not occur.
In FIG. 12(a) is shown an example recording head wherein a filter member is inserted into one part of a flow path. A filter chamber E is formed by cutting a shared area of an ink supply needle B, which serves as one part of a connection path with an ink cartridge A, and an ink flow path D, which communicates with a recording head C. A filter member F made of either an unwoven material or a mesh material is located at the filter chamber E, so that air bubbles that are generated or that become larger in the ink cartridge, or dust, are captured and can not enter the recording head C.
The tiny openings in the filter member are made smaller than the diameter of the nozzle opening in order to facilitate the capture of air bubbles, and the flow rate for ink is reduced by increasing the cross sectional area of the filter chamber E so as to prevent an increase in a flow path resistance due to the insertion of the filter material. Therefore, air bubbles that increase in size compared with the size of the mesh are stopped by a meniscus formed on the filter member F even during an ink refill operation or a recovery operation, at which time the ink flow rate at the filter member F is comparatively high. As a result, not only air bubbles can not be fully discharged from the filter F, but also the air bubbles accumulate on the surface of the filter F and interrupt the flow of ink, and the printing performance is drastically deteriorated.
To resolve this problem, it is one objective of the present invention to provide an ink-jet recording device that can eliminate the accumulation of air bubbles at a filter member, and that can supply an adequate volume of ink to a recording head for printing.
To achieve the above objective, according to the present invention, an ink-jet recording device comprises:
a recording head for receiving ink fed along a first ink supply path and for ejecting ink droplets;
a second ink supply path along which ink from an ink cartridge is fed to the first ink supply path; and
a filter member interposed in a shared area between the first ink supply path and the second ink supply path,
wherein an ink lyophilic property is provided for the filter member so that air bubbles that contact the filter material form a contact angle at substantially a right angle.
Since air bubbles on the surface of a filter member form contact angles that are substantially right angles, meniscuses that are formed at the filter member are weak, so that air bubbles can easily pass through the filter member and proceed downstream.